✨ [21] Merge Two Sorted Lists

Runtime 60 ms Beats 87.91% Memory 44 MB Beats 72.59%

Author: enkr1

21/my_solution.js

@@ -0,0 +1,65 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+class ListNode {
+  constructor(val, next) {
+    this.val = (val === undefined ? 0 : val);
+    this.next = (next === undefined ? null : next);
+  }
+}
+
+/**
+ * @param {ListNode} list1
+ * @param {ListNode} list2
+ * @return {ListNode}
+ */
+var mergeTwoLists = function (list1, list2) {
+  if (null === list1) return list2;
+  if (null === list2) return list1;
+
+  // dummy & head
+  let dummy = new ListNode(), head = dummy;
+
+  // go thru the linked list if either is null, update it a to b
+  while (list1 && list2) {
+    // console.log(`--> list`)
+    // console.log("-> list1")
+    // console.log(list1)
+    // console.log("-> list2")
+    // console.log(list2)
+    console.log("--> dummy")
+    console.log(dummy)
+    console.log(`----> A:${list1.val}, B:${list2.val}`)
+    // asc => check min
+    if (list1.val <= list2.val) {
+      // dummy.next = new ListNode(list1.val);
+      dummy.next = list1;
+      list1 = list1.next;
+      // console.log("New list1")
+      // console.log(list1)
+    } else {
+      // dummy.next = new ListNode(list2.val);
+      dummy.next = list2;
+      list2 = list2.next;
+      // console.log("New list2")
+      // console.log(list2)
+    }
+
+    // NOTE: THISISS!!!!!!!!
+    dummy = dummy.next;
+
+    // carry on the while if needed
+    dummy.next = (null === list1) ? list2 : list1;
+  }
+
+
+  console.log("head")
+  console.log(head.next)
+
+  return head.next;
+};
+mergeTwoLists(new ListNode(1, new ListNode(2, new ListNode(4))), new ListNode(1, new ListNode(3, new ListNode(4))))

21/solution.js

@@ -0,0 +1,41 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+class ListNode {
+  constructor(val, next) {
+    this.val = (val === undefined ? 0 : val);
+    this.next = (next === undefined ? null : next);
+  }
+}
+
+/**
+ * @param {ListNode} list1
+ * @param {ListNode} list2
+ * @return {ListNode}
+ */
+var mergeTwoLists = function (list1, list2) {
+  if (null === list1) return list2;
+  if (null === list2) return list1;
+
+  let dummy = new ListNode(), head = dummy;
+
+  while (list1 && list2) {
+    if (list1.val <= list2.val) {
+      dummy.next = list1;
+      list1 = list1.next;
+    } else {
+      dummy.next = list2;
+      list2 = list2.next;
+    }
+
+    dummy = dummy.next;
+
+    dummy.next = (null === list1) ? list2 : list1;
+  }
+
+  return head.next;
+};

README.md

@@ -16,6 +16,7 @@
 - [7. Generate Parentheses](./7/)
 - [11. Container With Most Water](./11/)
 - [15. 3Sum](./15/)
+- [21. Merge Two Sorted Lists](./21/)
 - [22. Generate Parentheses](./22/)
 - [23. Merge k Sorted Lists](./23/)
 - [33. Search in Rotated Sorted Array](./33/)
@@ -62,7 +63,7 @@ iex ./.../solution.ex
 
 Quick create in bash
 ```ssh
-chapter=23 && mkdir ./$chapter && touch ./$chapter/my_solution.js && touch ./$chapter/solution.js && alias x="node ./$chapter/my_solution.js"
+chapter=21 && mkdir ./$chapter && touch ./$chapter/my_solution.js && touch ./$chapter/solution.js && alias x="node ./$chapter/my_solution.js"
 ```
 
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